Carbon Dioxide

The three most important substances that make life possible are water, oxygen and carbon dioxide. The primary structural and functional element in all living things is carbon. All carbon in protein, fat, carbohydrate and other organic molecules in living things is derived from atmospheric carbon dioxide. Without atmospheric carbon dioxide, the life cycle will not complete.

The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, geosphere, hydrosphere and atmosphere of our planet. Carbon is stored in four major reservoirs :

- The atmosphere
- The biosphere ( including fresh water systems and ground soil)
- The oceans ( including dissolved inorganic carbon)
- The sediments ( incloding fossil fuels)

A Diagram of the Carbon Cycle

Carbon is exchanged between these reservoirs via sequences of various chemical reactions and biological processes. Carbon exists in the Earth's atmosphere primarily as the gas carbon dioxide. Although it is a very tiny percent of the atmosphere, it plays an important role in supporting life. In nature, carbon can then be released naturally back into the cycle in many different ways with the most common being respiration, decay of animal and plant matter, and the release of dissolved carbon dioxide from the oceans by marine life.